Image intensifier device using electron multiplier



Jan. 25,. 1966 G. WLGOODRICH IMAGE INTENSIFIER DEVICE USING ELECTRON MULTIPLIER Filed June 9. 1961 H m R D m ms WW E G R o E G ATTORNEY image intensifier of this invention;

3,231,746 Q IMAGE INTENSIFIER DEVICE USING ELECTRON MULTIPLIER Goodrich, Oak Par Michk, asslgnor to The Bendix Corporation, Southfiel Mleh., a corporation of Delaware r a Filed June 9, 1961, Ser. No. 116,059

12Clalrns. (Cl. 250-413) George W.

This invention pertains to an image intensifier having improved uniformity and resolution and more particularly, to an image intensifierhaving a photo-cathode, an electron multiplier and a phosphor screen. An embodiment of the invention is especially adaptable for use with color filters to provide multicolor inteni-fication.

a the image to improve resolution and uniformity.

40 which is made of a material well-known to-the art, that receives the electrons fromarray 32 on one side and emits corresponding light rays from the other thereof to provide an image similar-to the image received by array as, but intensified due toihe action of the inf dividual multiplier tubes 34., A lead 42 is to screen 40 to provide a voltage thereto.

Leads :1, as, as and 42 extend through the glass wall of enclosure and are connected to corresponding conductive rings 31a, 36a, 38a and 420 formed on the outer periphery of enclosure 20. Wipers 31b, 36b, 38b and Another object of this invention is to rotate the above intensifierdevice with a pair of color filters, one on either side of theintensifier to provide color intensification.

These and other objects will become more apparent when preferred embodiments of this invention are considered in connection with the drawings in which:

FIGURE 1 is a cutaway view in perspective of an FIGURE 2 is a simplified exploded viewof a device using color filtersron either side of an intensifier unit for color intensification and FIGURE 3 is a simplified perspective view of a device having color filters fused to an intensifier unit.

Glass envelope 20 is evacuated and hermetically sealed, is circular in shape and has a ring gear 22 attached to its outer circumference. 'A pinion gear 24, driven by motor26, engages ring gear 22 to rotate envelope 20 at a predetermined rate of speed. Idler gears 28 are positioned about ring gear 22 to facilitate rotation while centering gear 22.

Located inside envelope 20 and fused to a wall thereof is photo-cathode 30 which is constructed of material wellknown to the art for converting light rays impinging on one side thereof to corresponding electron emission from the other side thereof. A lead 31 is connected to cathode 30. I

Located adjacent photo-cathode 30 is an array 32 of channel multipliers of the type disclosed in Patent No. 3,128,408entitled Electron Multiplier filed April 20, 1960 by myself and W. C. Wiley which is the continuationin-part of an earlier application. Array 32 may be fiush with photo-cathode 30 or may be spaced slightly there- Each tube or channel 34 of array 32 is formed of an insulative material with a high resistive coating on the inside of the tube and with the tube diameter being relatively small compared with the tube length so that random velocities of electrons entering the tube will cause the electrons to impinge upon the resistive coating, causing secondary emission and multiplication as disclosed in the above application. I

The ends of the tubes on one side of array 32 are electrically connected to each other and to lead 36. The ends of the tubes on the other side of array 32 are electrically connected to each other and to lead 38. An accelerating field across the tubes can be provided by applying the proper voltage to leads 36, 38..

Adjacent to the other side of array 32 is phosphor screen 42b are in contact respectively with conductive rings 31a,

36a, 38a and 42a to provide these rings and their co'r- I responding voltage leads, with voltages from source 44. For a particular application, these voltages may be a minus 1700 volts applied to rings 31, a minus 1500 volts applied to ring 360, a plus 1500 volts applied to 38 and a plus-1700 volts applied to ring 42a. This would provide photo-cathode with a voltage of minus 1700volts, one end of array 32with minus 1500 volts and the other end of array 32 with a plus 1500 volts and phosphor screen s with 1700 volts. Therefore, electrons emitted by photopossible to project an image from the direction of arrow 29 directly onto the array 32. b

By revolving glass envelope 20 and the components therein, through means of motor 26 and gears 24 and 22, the various lines of the projected image from direction] of arrow 29 will be amplified by successivelydifierent port'- tions of photo-cathode 30 and multiplier tubes 34, and

phosphor screen 40. If the rotation is at a rate suiliciently high that several portions of the intensifier device pass before each point of the projected image during the retening effect. a

The speed of rotation, however, is limited by the per sistence" of the material used in the phosphor screen 40. For example, if the phosphor screen 40 continued to glow after being energized while the multiplier-has rotated, a blurring would occur. For this reason fast" phosphors are preferred in phosphor screen 40 so that the phosphor persistence is kept to a minimum. By making the phosphor screen 40 separate from array 32, it could be rotated at a lower rate than the array 32 and, this blurring would be eliminated even though the multiplier array 32 continued to rotate at a relatively'high rate.

Due to the large number of tubes in array 32, the rotative speed need not be great to have a given point of the image amplified by several tubes within the eye retentivity time to achieve the averaging effect. Also, a device can be constructed wherein the photo-cathode, amplifier section and phosphor can be moved independently of one another.

The device thus described is adaptable to color intensification by simply placing filters adjacent the photocathode 30 and a filter adjacent the phosphor screen 40. In FIGURE 2, which is an exploded view of'a color intensifier, is shown transmission filters 50, 52 for primary; colors placed on either side of a multiplier 54 which may be like the multiplier 20 shown in FIGURE 1, and rotat 3,231,746" I y Patented Jan. 25, 1966;

open ends of tubes 340i multiplier 5 able with the filters 50, 52. Each filter 50, '52 is divided filters correspond to each other. In fact, the number of color sections, or sets of primary colors, on each filter would be increased in normal usage so that for a given speed of rotation, more sets per second would pass the eye.

The filters may be fused as shown in FIGURE 3 to the outside of the intensifier section 54 or fused directly to the photo-cathode and phosphor screen inside the intensifier 54 or otherwise fixed to the intensifier. Motor 56 drives pinion 58 which engages ringgear 60 supported by idlers 62. Also, the filters could be separate from the intensifier 54 and rotated in synchronism at a preferred speed, while the intensifier is rotated at another speed.

To explain the manner in which the color intensification takes place, we will assume that the device shown in FIGURE 2 is stationary. An image, such as an automobile, is formed on filter 50 and each portion of the filter transmits its own color component of the image to intensifier 54 so that the blue sections transmit only the blue color of the image, the red sections transmit only the red sections of the image and the yellow sections transmit only the yellow portions of the image.

The light received by the intensifier 54 corresponds in intensity to the amount of the particular color of the image that is transmitted by a particular filter. If there is a large portion of blue in the image, then the intensity or amount of energy falling upon the intensifier from the blue filter will be large. After amplification by intensifier 54, this energy in the form of light waves will pass through a corresponding wedge of filter 52 which changes all light falling on it to blue, and we have an intensified reproduction of the blue portion of the image visible on filter 52. This is also true for the red and yellow portions.

Now by rotating the unit with sufficient speed so that at least one set of the primary colors passes a given point during retentivit-y time of the eye, the colors will merge to form a color image to the eye similar to the color image on filter 50.

Also, the filter sections can be chosen so that infrared or ultra-violet wavelengths can be detected. If the first filter has sections that pass only ultra-violet or infrared and the second filter has corresponding sections that pass a particular visible color, the infrared or ultra-violet radiations will be presented by that particular visible color.

The wavelength of received light may be transformed in any desired manner by designing the first filter, corresponding to filter 50, to pass wavelengths desired to be altered, passing through a converter such as a photocathode, which changes all wavelengths into an intermediate energy source such as electrons and then pass through a member to convert back into light waves, as with a phosphor member, and then through a second filter which passes only the wavelengths which are desired to be seen.

of course, other color combinations than those indicated by the drawing can be used. Also the movement of the intensifier section may be other than rotative to improve the resolution and uniformity. For example, oscillatory movement may be used. Other multiplier devices than the one illustrated in the preferred embodiment may be used and if the movement as described is imparted to the multiplier device, the advantages of this invention will accrue.

Although this invention has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

Having thus described my invention, I claim:

1. Apparatus for multiplying a two dimensional information conveying signal comprised of unit portions cornprising particle multiplying elements,

said particle multiplying elements arranged in a two dimensional array for receiving and multiplying the two dimensional signal,

electron receiving means for receiving the multiplied two dimensional signal, means for moving said particle multiplying elements coupled to said multiplying elements relative to the two dimensional signal at a sufi'icient rate so that the unit portions of the signal are multiplied by a plurality of multiplying elements without substantially changing the field of view resulting in a multiplication by an average of the multiplying elements, thereby improving resolution and uniformity, and

envelope means for enclosing said particle multiplying elements.

2. The apparatus of claim 1 with each of said particle multiplying elements comprising a surface defining a tubular passage,

each of said passages having its longitudinal dimension substantially greater than its diameter, said surfaces being disposed in closely spaced relationshi said surfaces being disposed in fixed relation to one another,

said surfaces being substantially parallel to each other to form an array of passages,

the ends of said surfaces at one end of said array being substantially coplanar and the ends of said surfaces at the other end of said array being substantially coplanar,

each of said surfaces having resistive and secondary electron emissive properties,

said plurality of surfaces being adapted for connection at each end of the array to a voltage source to produce an electrical current fiow through said resistive and secondary electron emissive surfaces to produce an electrical field in said tubular passages.

3. An image intensifier device for receiving and intensifying an image comprising,

light responsive particle emitting means,

particle amplifying means for amplifying the particles emitted from said emitting means and being positioned to receive the particle emission from said emitting means,

phosphor means being positioned to receive the amplified particles from said amplifying means,

said emitting means, amplifying means, and phosphor means each being a composite of elements,

means coupled to at least one of said emitting means,

amplifying means, and phosphor means to move at least one of said emitting means, amplifying means, and phosphor means relative to the received image at a sufficient rate so that different portions of said at least one means intercept and rwpond to a given point of said received image without changing substantially the field of view to improve' resolution and uniformity in the intensified image.

4. An image intensifier device for receiving and intensifying an image comprising light responsive particle emitting means being adapted to receive the image to be intensified,

particle amplifying means for amplifying the particles emitted from said emitting means and being positioned to receive the particle emission from said emitting means,

phosphor means for receiving the amplified particles at its input side and emitting light waves corresponding to said received amplified particles at its output side, said phosphor means heingpositioncd to receive the amplilietl particles from said amplifying means, means coupled to at least one of said emitting means, amplifyingmeans, and phosphor means to move at least one of said/emitting means, amplifying means, and phosphor means relative to the received image at a sufficient rate so that different portions of said at least one means intercept and respond to a given point of said received image without changing sub stantially the field of view to improve resolution and uniformity in the intensified image, envelope means for enclosing said emitting means, am-

plifying means, and phosphor means. 5. An image intensifier device for receiving and intensifying an image comprising light responsive particle emitting means being adapted to receive the image to be intensified, particle amplifying means for amplifying the particles emitted from said emitting means and beingpositioned to receive the particle emission from said emitting means, phosphor means being positioned to receive the amplified particles from said amplifying means, means coupled to at least one of said emitting means, amplifying means, and phosphor means to move repetitiously and continuously at least one of said emitting means, amplifying means, and phosphor means relative to the received image at a sufficient rate so that different portions of said at least one means intercept and respond to a given point of said received image without changing substantially the field of view to improve resolution and uniformity in the intensified image, envelope means for enclosing said emitting means, am-

plifying means, and phosphor means. 6. An image intensifier device for receiving and inten' sifying an image comprising 1 light responsive particle emitting means being adapted to receive the image to be intensified, particle amplifying means for amplifying the particles emitted from said emitting means and being positioned to receive the particle emission from said emitting means, phosphor means being positioned to receive the amplified particles from said amplifying means, means coupled to at least one of said emitting means, amplifying means, and phosphor means to move rotatively and continuously at least one of said emitting means, a mplifying means and phosphor means relative to the received image at a sufficient rateso that different portions of said at least one means intercept and respond to a given point of said received image without changing substantially the field of view to improve resolution and uniformity in the intensified image,

envelope means for enclosing said emitting means, am-

plifying means, and phosphor means.

7. The image intensifier of claim 5 with said amplifying means comprising an array of individual particle amplifying tubes,

each of said tubes having a continuous resistive secondary emissive coating therein,

means coupled to said emitting means, amplifying means, and phosphor means to move said emitting means, amplifying means, and phosphor means relative to the received image at a sufficient rate so that different portions of said means that are moved in-. tercept and respond to a given point of saidreceived image without changing substantially the field of view to improve resolution and uniformity in the intensified image,

envelope means for enclosing said emitting means, am-

plifying means, and phosphor means.

9. The intensifier of claim 4 with a first: color filter means being placed between the image to be intensified and the light responsive particle emitting means,

a second color filter means being placed at the output side of said phosphor means,

said first and second color filter means being divided into color zones whereby images may be intensified in color.

10. The intensifier ofclaim 9 with said first and second color filter means having substantially identical color zones and being in rigid relationship to the particle amplifying means.

11. The intensifier of claim 9 with said envelope means having two supporting walls substantially parallel to one another,

said first color filter means being fused to one of said .walls and said second color filter means being fused to the other of said walls.

12. The apparatus of claim 2 with l voltage means being connected to each end of the array to produce an electrical current flow through said resistive and secondary electron emissive surfaces to produce an electrical field in said tubular passage.

References Cited by the Examiner UNITED STATES PATENTS 2,210,034 8/1940 Keyston 315-12 2,374,916 5/1945 Biedermann 250-213 X 2,422,937 6/1947 Szegh-o l78-5.4 2,727,182 12/ 1955 Francken 250-21'3 X 2,976,447 3/1961 McNaney 250-213 X 3,058,003 10/1962 Michlin 250-213 3,115,807 12/1963 Craig et at 178-5.2 X 3,128,408 4/1964 Goodrich et al. 250213 X RALPH GLNILSON, Primary Examiner. WALTER STOLWEIN, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,231,746 January 25, 1966 George W. Goodrich I It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 21, for "dieffrent" read different column 2, line 16, for "rings" read ring column 6, lines 9 to 11, strike out "and being positioned to receivethe particle emission from said emitting means".

Signed and sealed this 17th day of January 1967.

SEAL) Lttest:

ERNEST W. SWIDER EDWARD J. BRENNER Lttesting Officer Commissioner of Patents 

8. AN IMAGE INTENSIFIER DEVICE FOR RECEIVING AN INTENSIFYING AN IMAGE COMPRISING LIGHT RESPONSIVE PARTICLES EMITTING MEANS BEING ADAPTED TO RECEIVE THE IMAGE TO BE INTENSIFIED, PARTICLE AMPLIFYING MEANS FOR AMPLIFYING THE PARTICLES EMITTED FROM SAID EMITTING MEANS AND BEING POSITIONED TO RECEIVE THE PARTICLE EMISSION FROM SAID EMITTING MEANS AND BEING POSITIONED TO RECEIVE THE PARTICLE EMISSION FROM SAID EMITTING MEANS, PHOSPHOR MEANS BEING POSITIONED TO RECEIVE THE AMPLIFIED PARTICLES FROM SAID AMPLIFYING MEANS, MEANS COUPLED TO SAID EMITTING MEANS, AMPLIFYING MEANS, AND PHOSPHOR MEANS TO MOVE SAID EMITTNG MEANS, AMPLIFYING MEANS, AND PHOSPHOR MEANS RELATIVE TO THE RECEIVED IMAGE AT A SUFFICIENT RATE SO THAT DIFFERENT PORTIONS OF SAID MEANS THAT ARE MOVED INTERCEPT AND RESPOND TO A GIVEN POINT OF SAID RECEIVED IMAGE WITHOUT CHANGING SUBSTANTALLY THE FIELD OF VIEW TO IMPROVE RESOLUTION AND UNIFORMITY IN THE INTENSIFIED IMAGE, ENVELOPE MEANS FOR ENCLOSING SAID EMITTING MEANS, AMPLIFYING MEANS, AND PHOSPHOR MEANS. 